Grade 8 - Mechanical Systems Unit Exam

 $W=FxD$  How much work is produced when 350 N is used to move a car 5 m?

• 70 J

• 1750 J

• 355 J

• 175 J

What is a machine?

• an object that has Artificial Intelligence.

• an object that is designed to take over the earth in 2050.

• a device that changes force by reducing it over a larger distance.

• a mechanism that is used to decrease the amount of work done.

What is mechanical advantage?

• The advantage a machine has over a bicycle

• A measure of how much a simple machine reduces work

• A measure of when is the best time to use a simple machine

• the number of times a machine increases input force

Tags

NGSS.HS-PS2-3

What is input force?

• the force one puts into a machine

• the force which an effort force must overcome in order to do work on an object via a simple machine.

• the force the machine exerts on a object

• the output work times the input distance

What is output force?

• the force required by a machine in order to accomplish work (the force you put on the machine)

• The force that is created by a machine

• the force the machine exerts on a object

• the output work times the input distance

Tags

NGSS.MS-ETS1-1

What is input distance?

• the force required by a machine in order to accomplish work (the force you put on the machine)

• the force which an effort force must overcome in order to do work on an object via a simple machine.

• the distance an input force acts through

• the output work times the input distance

What is output distance?

• the force required by a machine in order to accomplish work (the force you put on the machine)

• the force which an effort force must overcome in order to do work on an object via a simple machine.

• the distance an input force moves a machine

• the distance through which the output force is exerted

How can you determine the mechanical advantage of a pulley system?

• Count the number of rope/cable segments on each side of the pulleys, including the free end. If the free end is to be pulled down, subtract 1 from this number.
• Count the number of rope/cable segments on each side of the pulleys without including the free end.
• Count the number of rope/cable segments on the central pulleys.
• Count the number of rope/cable segments on each side of the pulleys, including the free end. If the free end is to be pulled down, subtract 10 from this number.

 $MA=\ \frac{Output\ F}{Input\ F}$  If the weight of the block is 10N, how much force does one have to apply to lift it using this pulley (MA=2)?

• 2N

• 5N

• 10N

• 15N

What is the mechanical advantage of this pulley system?

• 2
• 3
• 4
• 5

Tags

NGSS.MS-PS2-2